Ground-to-water heat pumps use the energy stored in the upper layers of the soil. The heat pump thus draws heat from, for example, the area of your garden. This thermal energy is collected by means of a horizontal ground collector.
How a ground-to-water heat pump works
Beneath the ground surface, at a depth of about 1,2 m, hoses are laid in the soil, made up of a number of loops of equal length and filled with an antifreeze mixture.
The collectors are connected to the heat pump via flow and return water manifolds and collecting pipes (using the so-called Tichelmann principle).
The piping transfers heat between the ground and the heat pump. Thanks to the ground’s ability to store heat, the soil temperature fluctuates considerably less than the air temperature.
If your family home has a suitable plot, the ideal choice for you is a heat pump with ground collectors, one of the best options.
Features of a ground-to-water heat pump
Pros
- Low investment costs compared with geothermal boreholes.
- The price of a complete ground/water heat pump system with ground collectors is almost comparable to the price of an air/water heat pump.
- A ground-to-water heat pump has significantly lower electricity consumption than with heat pumps that draw heat from the air.
- Long service life of both the heat pump and the ground collector.
- A silent, maintenance-free solution.
Cons
- A ground-to-water heat pump system with a horizontal ground collector requires a sufficiently large plot of land around the building, and the use of the land is then limited.
- The soil must allow excavation to the required depth.
- Because of the placement of the horizontal ground collector, the positioning of any other future structures on the plot is restricted.
How a horizontal (ground) collector works
A horizontal ground collector is essentially a large solar collector, supplemented by a large clay heat accumulator with an annual charging and discharging cycle.
A heat pump with a horizontal ground collector works by drawing energy from the ground beneath it (about 2% of the energy) and, above all, energy from the layer of soil above it (about 98% of the energy), where solar energy from the sun is stored.
For the heat pump’s needs, a horizontal ground collector extracts from the ground over a year only about 2,5% of the energy the ground gains from solar energy during that year.
As a result, it cannot run out of energy even in the long term, because it regenerates during the summer months.
